Building Spatial Databases based on Location

HES 505 Fall 2022: Session 15

Matt Williamson

Outline for today

  • Update on assignments

  • Refresher: Building a spatial analysis workflow

  • Building a database for an analysis (part 2) based on location

Update on assignments

  • Assignment 2 due by 14 Oct

  • Self-assessment due 18 Oct

  • Resubmits

  • Final Project

Objectives

By the end of today you should be able to:

  • Create new features based on topological relationships

  • Use topological subsetting to reduce features

  • Use spatial joins to add attributes based on location

Revisiting Spatial Analysis

What is spatial analysis?

“The process of examining the locations, attributes, and relationships of features in spatial data through overlay and other analytical techniques in order to address a question or gain useful knowledge. Spatial analysis extracts or creates new information from spatial data”.
— ESRI Dictionary

Workflows for spatial analysis

courtesy of Humboldt State University

  • Align processing with objectives

  • Imagining the visualizations and analysis clarifies file formats and variables

  • Helps build reproducibility

Databases and Attributes

courtesy of Giscommons

  • Attributes: Information that further describes a spatial feature

  • Attributes → predictors for analysis

  • Last week focus on thematic relations between datasets

    • Shared ‘keys’ help define linkages between objects

  • Sometimes we are interested in attributes that describe location (overlaps, contains, distance)

  • Sometimes we want to join based on location rather than thematic connections

    • Must have the same CRS